Cam operated repeat mechanism



May 30, 1967 L. P. FRECHETTE ET AL 1 3,322,254

CAM OPERATED REPEAT MECHANISM 2 Sheets-Sheet 1 Filed Aug. 17, 1966 MN MW kw @w u NM mm INVENTORS LEO P FRECHETTE EDGAR G. LIZOTTE ATTORNEYS May 30, 1967 FRECHETTE ET AL 3,322,254

CAM OPERATED REPEAT MECHANISM 2 Sheets-$heet 2 BY XIX/b MMrwvJ/Haw/ ATTORNEYS Filed Aug. 17, 1966 United States Patent O 3,322,254 CAM OPERATED REPEAT MECHANISM Leo P. Frechette, West Hartford, and Edgar G. Lizotte,

Winsted, Conn., assignors to Royal Typewriter Company, Inc., Hartford, Conn., a corporation of Delaware Filed Aug. 17, 1966, Ser. No. 573,081 3 Claims. (Cl. 197-17) This is a continuation-in-part of application Ser. No. 276,237, filed Apr. 29, 1963, now abandoned.

This invention relates to typewriter apparatus; more particularly it relates to typewriter apparatus having cyclic mechanism operative to recycle a power operated unit at a controlled rate, and more specifically it relates to typewriter apparatus wherein said cyclic mechanism is characterized by rotatable cam means operable in response to manual means to continually recycle a power operated unit a a controlled rate.

One of the objects of the invention is to provide a cyclic mechanism of the above nature that is characterized by structural simplicity and operational reliability over an extended period of use.

Another object is to provide such a mechanism that is inexpensive to manufacture, easy to install in the writing machine, and that requires a minimum of adjustment after final assembly of the machine and during field use thereof.

Still another object is to provide a repeat mechanism which can be applied to any character key or function key where repeat operation thereof is desired or necessary.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a side elevational view showing the elements of the repeat mechanism in the normal position;

FIGURE 2 is an exploded View of the repeat mechanism.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown a type bar 9 pivotally mounted on a segment wire 10, and adapted to be driven to a printing position at a carriage supported platen 11, by a type bar actuating link 12, which is articulately connected between the type bar 9 and a sub-lever 13. The sub-lever 13 has its lower end pivotally supported on a fulcrum 14 supported by a bar 14', which is connected to the machine frame (not shown) by any suitable means. The type bar 9 is yieldably biased towards the normal rest position, shown in FIGURE 1, by means of a spring 15 fastened to the depending finger 13a of sublever 13. Pivotally mounted, as by stud 16 on the lever 13, is an oscillatable cam 17 having an eccentric roughened periphery 18 that is adapted to be swung into frictional engagement with the outer cylindrical surface 24} of a rubber coated power roll 21, which is continuously rotated in a counterclockwise direction, as indicated by arrow A in FIGURE 1. Cam 17 is provided with a depending arm 17a into which an adjustable knock-off screw 22 is threaded. The end 2212 of the screw is adapted during the operation of the type action to be engaged by a fixed machine frame stop 23, so as to effectively disengage the cam 17 from the power roll 21 and terminate the drive; momentum completing the type action. A spring 24 biases the cam 17 to a normal counterclockwise position wherein depending arm 17a engages a stop 39 which is integral with lever 13. The construction and operation of the above described type bar operating linkage is more or less conventional and needs no further explanation here.

As best viewed in FIGURE 2, a bent off end 25a of a depending by-pass arm 25, pivotally mounted on cam 17 by a stud 26 and biased clockwise by a spring 55, overlies the free end 27a of a rockable trip lever 27, which is journalled at one end 27c on a fulcrum rod 29 fastened in a bar 31 carried by the machine frame (not shown). The trip lever 27 is so shaped as to extend downwardly, rearwardly and upwardly terminating in the free end 27a. A U-shaped bail 28 is pivotally mounted on the fulcrum rod 29, which extends through the ears 28c thereof. A depending leg 28]), integral with and extending from the left ear of the bail 28, as viewed in FIGURE 2, is adapted to be engaged and rocked by an associated depending leg 32a of a key lever 32. Bail 28 further includes a bent over stop 28:; integral with and extending forwardly and laterally thereof to overlie an arm 27b of trip lever 27 which extends forwardly from fulcrum rod 29. Thus, as is evident when the key lever 32 is depressed, its leg 32a will rock trip lever 27 via bail 28, as will be more fully described below. The purpose of the bail 28 is to transmit the motion of the key lever 32 to the trip lever 27, inasmuch as in this particular machine, the key lever is lo cated on the extreme right side, and the associated trip lever and action is located toward the center of the machine. Obviously, if the key lever and its associated trip lever were aligned with one another, the key lever could directly operate the trip lever and the bail could be eliminated.

Key lever 32 is pivotally mounted on the bar 31, by any suitable means, such as by a fulcrum shaft 33, and is biased against a normal upper stop 34 by a suitable frame anchored spring 35. Trip lever 27 is provided with a frame mounted spring 36, to return the trip lever 27 and thus the bail 28 (via trip lever arm 27b and bail stop 28a) from the operating position to the position shown in FIGURE 1.

In operation, when the key lever 32 is depressed toward lower stop 37, the resultant counterclockwise movement of bail 28 elevates the free end 27a of trip lever 27 which serves via by-pass arm 25 to swing the cam 17 in a clockwise direction against the action of spring 24 into operative engagement with the rotating power roll. Thereafter the type bar 9 will be power driven through an operative printing stroke and will then be spring returned to its normal FIGURE 1 position in the usual manner. If the key lever 32 is held depressed, a repeat type action is impossible inasmuch as during the return of the cam to its FIGURE 1 position, the elevated trip lever end 27a will abut the rearward edge of the bypass arm 25. Thus the by-pass arm will be pivoted clockwise around stud 26 by the elevated trip lever, preventing a repeat action until the key lever is released. After the key lever is released, thereby lowering trip lever end 270, the bypass arm 25 will be pivoted by spring 55 to the FIGURE 1 position overlying trip lever end 27a, thus permitting another type action when the key lever is depressed.

In general, the construction described so far does not in and of itself constitute the invention. The invention resides in other parts to be described and combinations of such other parts with each other and with parts already described.

In the construction shown as embodying the present invention in a preferred form, a manually depressible key 40 is mounted on the outer end of a bar 41 which extends through a slot 42 formed in a mask M of tthe typewriter thus to be readily accessible to a typist. Bar 41 is mounted on a lever 43 pivotally carried by a pin 44 secured to a portion of the machine frame 45. Lever 43 is biased clockwise around pin 44 by a spring 46 such that a stop 47a of arm 47 which is formed on lever 43 contacts machine frame edge 45a. The inner end 43a of lever 43 is pivotally connected to the upper end 48:: of a link 48 whose lower end 481; is connected to a forwardly extending arm 49a of a bell crank 49. The other depending arm 4% of hell crank 49 is pivotally secured by a pin 50 to a rearwardly and upwardly extending arm 5101 on the left end of a bracket 51 supported by bar 31. Thus when key 49 is depressed such that stop 47]; of arm 47 contacts the machine frame 45 at 45b, the bell crank 49 is rocked clockwise around the pin 50.

Arm 51a is preferably formed integrally with the bracket 51 which is secured in any suitable manner to the bar 31 and is also provided with an upwardly extending arm 51b on the right end thereof. A shaft 52 has one end 52a journalled at the bend in bell crank 49, the other end 52b of shaft 52 being loosely journalled in the arm 51b, such that shaft end 52a may pivot or swing to the right, as viewed in FIGURE 2, about its connection to the arm 51b, when bell crank 49 is rocked clockwise. In the rest or normal position shown in FIGURE 2, the shaft journals lie in a plane parallel to the axis of rotation of power roll 21. Shaft 52 is formed intermediate its ends with an offset or eccentric portion 520 which serves as a camming means to drive, when shaft 52 is rotated, a cam follower or bail finger 53 extending upwardly from bail 28. The bail finger 53 may, of course, be integrally formed with trip lever 27, as shown in the hereinbefore mentioned application 276,237. A drive roll 54 is securely fastened to the straight portion of shaft end 52a, and rotates shaft 52 when the shaft is pivoted about its connection to arm 51b, causing the drive roll 54 to be engaged with power roll 21, whereby the trip lever 27 will be repeatedy rocked around fulcrum 29, as will now be described.

It will now appear that when bell crank 49 is rocked clockwise by depression of key 4%, as described above, shaft end 52a, and accordingly roll 54, are carried downwardly, whereby power roll 21 is engaged by and drives roll 54 to rotate shaft 52, which in turn will cause the eccentric portion 520 of shaft 52 to rock the follower finger 53. Since follower finger 53 is integral with bail 28, it is returned to the starting position, shown in FIGURE 2, when it is no longer in the path of shaft portion 520, by the same spring 36 which returns the trip lever and hail. Although tthe path of motion of the cam means or shaft portion 52c is symmetrical around the axis of rotation of shaft 52, the motion of portion 52c with respect to finger 53 is eccentric. Thus, as is well known in the art, other machine elements, such as an eccentric cam, may be used in place of a shaft provided with an eccentric portion 520 to provide the desired camming action on follower finger 53.

counterclockwise rocking of the finger 53 around fulcrum rod 29 will rock trip lever 27, via bail stop 28a, thereby initiating a powered type action. Thus, as long as key 40 is held depressed, the type action associated with type bar 9 will be repeatedly triggered to drive the type bar through operative printing strokes, one for each revolution of drive roll 54. Upon release of key 40 roll 54 disengages from power roll 21 and the recycling or repeat operation of the type action ceases. It may also be seen that the number of cycles per second of any repeat operation selected may be attained, up to a reasonable maximum, by adopting an appropriate diameter drive roll 54.

As will be understood in the art, the repeat mechanism may be connected to other apparatus besides the type bar for effecting repeated operations of a single selected function. For example, the bail 28 may be positioned in association with a backspace trip lever or a line space trip lever (in the same fashion as the bail is associated with the trip lever 27 in the embodiment hereinbefore described) to provide either repeat backspace or platen indexing operations, when an associated key 40 is held depressed.

Thus We have provided a repeat mechanism which attains the several objects set forth above in a thoroughly practical and etficient manner.

It should be understood that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

1. In a repeat mechanism for an electric typewriter having a continuously rotating power roll, and a power unit connected to drive a selected typewriter function when coupled to said power roll,

a rockable trip lever adapted when rocked to effect the coupling of said power unit with said power roll,

a depressible key lever for rocking said trip lever once for each depression, and

alternate means for rocking said strip lever at a controlled cyclic rate comprising,

cam means,

a rockable support,

means for rotatably mounting said cam means on said rockable support,

manually operable means for rocking said support thereby to couple said cam means to said power roll whereby said cam means is rotated,

said trip lever including a cam follower operable by said rotating cam means for repeatedly rocking said trip lever for as long as' said manually operable means is held operative.

2. A power operated typewriter or prising the combination of:

(a) at least one type bar movable between a rest position and a print position;

(b) a continuously rotating power roll;

(c) a power unit comprising a pivoted lever having a first cam means pivotally mounted thereon;

(d) means connecting said pivoted lever to said type bar;

(e) a rockable trip lever;

(f) a depressible key lever adapted upon depression to rock said trip lever to effect coupling of said first cam means with said power roll thereby driving said type bar through a single operating stroke;

(g) a rockable support;

(h) a second cam means rotatably mounted upon said rockable support;

(i) a cam follower operatively associated with said second cam means and said trip lever; and,

(j) manually operable means adapted to rock said rockable support to move said second cam means into rolling engagement with said power roll thereby to rock said trip lever at a controlled cyclic rate to repeatedly couple said first cam means to said power rolls as long as said second cam means is held into engagement with said power roll thus providing repeated operating strokes of said type bar independently of said key lever.

3. Apparatus as defined by claim 2 wherein said second cam means comprises:

(a) a shaft rotatably mounted on said rockable sup- (b) eccentric means on said shaft; and,

(c) a roller mounted on said shaft and adapted to be moved into and out of engagement with said power roll by said rockable support.

like machine com- References Cited UNITED STATES PATENTS '15 E.- URR, Assistant Examiner. 

1.IN A REPEAT MECHANISM FOR AN ELECTRIC TYPEWRITER HAVING A CONTINUOUSLY ROTATING POWER ROLL, AND A POWER UNIT CONNECTED TO DRIVE A SELECTED TYPEWRITER FUNCTION WHEN COUPLED TO SAID POWER ROLL, A ROCKABLE TRIP LEVER ADAPTED WHEN ROCKED TO EFFECT THE COUPLING OF SAID POWER UNIT WITH SAID POWER ROLL, A DEPRESSIBLE KEY LEVER FOR ROCKING SAID TRIP LEVER ONCE FOR EACH DEPRESSION, AND ALTERNATE MEANS FOR ROCKING SAID STRIP LEVER AT A CONTROLLED CYCLIC RATE COMPRISING, CAM MEANS, A ROCKABLE SUPPORT, MEANS FOR ROTATABLY MOUNTING SAID CAM MEANS ON SAID ROCKABLE SUPPORT, MANUALLY OPERABLE MEANS FOR ROCKING SAID SUPPORT THEREBY TO COUPLE SAID CAM MEANS TO SAID POWER ROLL WHEREBY SAID CAM MEANS IS ROTATED, SAID TRIP LEVER INCLUDING A CAM FOLLOWER OPERABLE BY SAID ROTATING CAM MEANS FOR REPEATEDLY ROCKING SAID TRIP LEVER FOR AS LONG AS SAID MANUALLY OPERABLE MEANS IS HELD OPERATIVE. 